Under what circumstances can you use a z-test instead of a t-test to compare a sample against a population?

A union of restaurant and foodservice workers would like to estimate the mean hourly wage, u, of foodservice workers in the U.S. this year The mean hourly wage last year was $8.08, and there is good reason to believe that this year's value is different from last year's. The union decides to do a statistical test to see if the value has indeed changed. The union chooses a random sample of this year's wages, computes the mean of the sample to be $7.78, and computes the standard deviation of the sample to be $1.20. Based on this information, complete the parts below. (a) What are the null hypothesis H. and the alternative hypothesis H₁ that should be used for the test? H₂ : O H₁ :0 (b) Suppose that the union decides not to reject the null hypothesis. What sort of error might it be making? (Choose one) ▼ (c) Suppose the true mean hourly wage for foodservice workers in the U.S. this year is $8.08. Fill in the blanks to describe a Type I error. A Type I error would be (Choose one) when, in…

Can you think of any flaws in the One-Sample Z-Test for Mean?

The critical boundaries for a hypothesis test are z = +1.96 and -1.96. If the z-score for the sample data is z = -1.90, what is the correct statistical decision?​

A chi-square homogeneity test is to be conducted to decide whether a difference exists among the distributions of a variable of seven populations. The variable has four possible values. What is the degrees of freedom for the x²-statistic? The degrees of freedom is (Simplify your answer.)

You can reduce the risk of a Type I error by using a larger sample. True or False?

All other conditions being equal, does a larger sample size increase or decrease the corresponding magnitude of the z or t value of the sample test statistic?

A researcher wants to test the effectiveness of a new drug to treat asthma.  One hundred patients with chronic, stable asthma were randomly assigned to one of three groups to receive a placebo (0mg), 1mg of drug, or 5 mg of drug.  After treatment, a doctor tested the patient’s forced expiratory volume for 1 second (FEV1).  Which statistical test would be best to determine if there is a significant difference between groups?     one-sample t-test     dependent samples t-test     independent samples t-test     ANOVA

Opposing a random sample of size and equal 16A sample average of 185 it is observed the P value of the sample statistic is

What conclusions can be drawn from a study with a “statistical significance” result?   What information do you look at to evaluate whether an effect obtained in an experiment is large enough to have a “practical” or “clinical” significance?